Summer has definitely arrived in Prescott. Now that summer is here, there is more daylight to ride during, and plenty of nice sunny days to be outside. To go along with this time of the year we have started to see daytime high temperatures reaching the high 80’s and even 90 degrees. During these days of higher temperatures, and likely more exercise due to trail riding, it is important to understand how to protect our horses from the hotter weather so that they can stay as cool and comfortable as possible.

Dehydration

One of the biggest things to try and protect our horses from this time of year is dehydration, which when left “untreated” can lead to life-threatening heat stress. It is important this time of the year that a horse owner is comfortable on how to assess their horse’s hydration status and common signs of an impending problem from the heat. First it is important to understand that the thirst mechanism in the body is stimulated by dehydration. Therefore you, or your horse, don’t actually become thirsty until they are slightly dehydrated. Thus during the summer, as during all times of the year, it is important that a horse have access to fresh clean water. There are two simple ways to assess your horse’s hydration status. The first technique is the skin tent method. This is where you pinch up the horse’s skin at the point of its shoulder and pull it up away from the neck. After releasing the skin you should count how many seconds it takes for the skin to flatten back out. In a normal hydrated horse this will take a second or less. If it takes 2-3 seconds for the skin to flatten out, then your horse is dehydrated and should be offered water immediately. If it takes 4-5 seconds or longer, then it is recommended to contact your veterinarian as simply offering them water may not be enough at that degree of dehydration. The second test that you can do to assess your horse’s level of hydration is the capillary refill time (CRT). This is where you press firmly on your horse’s gum line until the pink tissue blanches to a white color. Once you remove your thumb or finger, then you should count the number of seconds it takes for the pink color to return. Normal is less than 2 seconds, while a dehydrated horse will have a CRT of 3 or more seconds. Both of these tests are simple and quick to perform, and can be performed while out enjoying a nice trail ride or other activity so that we can help to protect
our horses.

Signs of a possible heat related problem

Although the above two tests are simple to perform, it is also important to recognize other signs of a possible impending heat related problem. When exercising a horse this time of the year we would expect our horse to begin to sweat in response to the heat. It is important however to note when a horse does NOT sweat when you would expect it to do so. There are two reasons for a horse to not sweat when they should do so. The first is a condition called anhydrosis, or the lack of an ability to sweat. The cause of this condition is poorly understood but usually occurs in horses that sweat for prolonged periods of time in hot and humid climates. What is most important to understand about anhydrosis is that the horse has lost the ability to sweat during high temperatures, and thus cannot help cool it off, and thus is susceptible to heat stress. The second reason that a horse wouldn’t be sweating when we would expect it to do so is that it is already dehydrated to the point that the body doesn’t have enough fluid left to produce sweat. Either way, both of these conditions are serious, and it is recommended that you contact your regular veterinarian on what to do to help your horse. Other signs to look for that may indicate an impending heat related problem to check your horse’s rectal temperature after a hard work in the heat. A core body temperature of 104 or greater will dramatically reduce a horse’s metabolic activity, and if the temperature continues to rise can lead to organ system shutdown. Temperatures of this level are often accompanied by rapid and irregular breathing, a depressed attitude, lack of sweating, dark gum color, prolonged CRT and an elevated heart rate. These are all signs of a potentially serious problem, and you should seek veterinary care immediately.

Treatment

Some heat related problems require that a horse be treated in a clinic with aggressive intravenous fluid therapy, but what about the ones that are not as bad, what can be done for them? Obviously it is always best to try and prevent these problems by making sure that your horse is given ample opportunities to drink fresh clean water. However, there are some basic things that a horse owner can do in the face of dehydration to help their horses. The first thing to do is to begin cooling the horse off. This can be done by getting the horse into whatever shade you can. If you have the ability at the time, then the horse should also be rinsed with cool or cold water. After rinsing the horse with cool or cold water, then you should scrape it off, and repeat the process. Next the horse should be offered fresh water. Despite older beliefs, a horse that is hot may be offered cold drinking water without fear of it causing the horse to colic. A hot horse should also be offered an electrolyte supplement, as they lose a large volume of electrolytes in their sweat. This can be done with a commercial electrolyte paste or by giving them access to a salt block. The electrolytes sodium and chloride are not found in high quantities in a horse’s hay, and are lost in high volumes during sweating. Therefore it is important to ensure that a horse has these essential electrolytes replaced after a period of exercise during hot weather. An additional important part of treating heat related problems in the horse is to ensure that they have ample time to recover after treatment. Therefore if you have to treat a horse for heat related issues then it is important to give them a couple of days off to allow their body to recover what they have lost in fluids and electrolytes.

These are some simple things that you as a horse owner can do to help stave off heat related problems in your horse during the hotter days of summer. As with any other situation where you are concerned about your horse’s health, it is always wise to consult with your veterinarian regarding the symptoms you are seeing and how you approach treatment. A team approach to horse healthcare is always the best approach.